倾斜裂隙介质反透射系数研究  

Study on the reflection-transmission coefficients of elastic waves in the media with dipping fractures

作　　者：蔡晓刚[1] 陈晓非[2] 

机构地区：[1]北京大学地球与空间科学学院,北京100871 [2]中国科学技术大学地球与空间科学学院,合肥230026

出　　处：《地球物理学报》2009年第5期1253-1262,共10页Chinese Journal of Geophysics

基　　金：地震行业科研专项基金(20070804);国家自然科学基金(40521002)资助

摘　　要：自然界的裂隙排列并非都是直立的,在复杂地壳应力作用下裂隙排列很可能是倾斜的.本文从各向异性弹性动力学基本方程出发,在特征矩阵方法基础上提出了计算任意倾斜裂隙介质水平界面上的反射、透射系数的简单方法,并利用该方法计算了倾斜裂隙介质P-P波、P-SV波和P-SH波的反透射系数.结果表明,P-P波、P-SV波和P-SH波的反透射系数与倾斜裂隙的倾角、测线方位以及偏移距这些物理参数之间存在一定的依赖关系.此外我们计算了C波的零入射相角时的反射系数,发现该反射系数跟裂隙倾角、裂隙的方位角有着明显的对应规律,且各向异性越强时,该反射系数越大.这些研究对于深入了解倾斜裂隙的动力学特征具有一定的意义.Not all fractures in the nature are vertical but may be dipping owing to complex tectonic stress. In this paper, we computed the reflection and transmission coefficients for these complex models by generalized reflection and transmission coefficients matrix methods. The result shows that P-P, P-SV, and P-SH reflectivities all rely on the tilt angle of fracture and survey azimuth. Furthermore we also calculated the reflectivity of zero-offset PS-converted wave, which has an obvious relation with the tilt angle and azimuth of the dipping fractures and the strength of anisotropy. These studies above all have some great significance to understand the dynamic properties for dipping fractures.

关 键 词：C波 零相角入射 倾斜对称轴TI介质 

分 类 号：P315[天文地球—地震学]